There is a big and very important difference between the two. Reading the Bible can be done by anyone. The Bible can be read cynically, scientifically, studiously and obligatorily. But, meditation on the Word of God is only done by those who seek to plant the Word in their hearts and desire to be changed. “Reading” makes no assumption that personal application is made; meditating implies that the words are pondered and applied.
“This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then thou shalt make thy way prosperous, and then thou shalt have good success” (Josh. 1:8).